1. Field of the Invention
The present invention relates to an apparatus and a method for generating data used for a card having a face photo thereon (hereinafter referred to as a photo card) and to an apparatus and a method for generating the photo card. The present invention also relates to a program for causing a computer to execute the methods of generating the photo card data and the photo card.
2. Description of the Related Art
Photo ID cards having face photos for identifying individuals have been conventionally used (see Japanese Unexamined Patent Publication No. 6(1994)-199080). In order to generate such an ID card, a person is firstly photographed with a nametag representing the name of the person and a bar code of his/her employee identification number and the like, and the photograph is printed on printing paper. The face image and the bar code printed on the paper are then read with a scanner, and data files having property data such as the name and date of birth of all employees are searched, for the property data corresponding to the face image, according to the bar code that has been read. The property data found in this manner are output to a printing unit, and the printing unit prints the property data as character data on the ID card. According to internal processing, the printing unit also trims only the face image from image data that have been obtained by the scanner, and prints the trimmed data on the ID card.
Meanwhile, an automatic trimming apparatus has also been proposed for automatically trimming the face of a person from an image representing the upper half of the person so that the face is positioned in a predetermined position in a trimming frame of a predetermined size (see Japanese Unexamined Patent Publication No. 2000-36032). In this automatic trimming apparatus, the position of the face is determined in the following manner. Firstly, the top of the head is detected from the image representing the upper half of the person, and a skin-color area below the top of the head is extracted as a face image. A position of chin is then detected in the face image, and the position of the face is determined based on the top of the head and the position of the chin.
Furthermore, authentication of individuals has also been carried out. For authentication, personal information for identifying an individual is stored in an ID card, and the personal information is read from the ID card upon entering or leaving a security area or access to an information system. The personal information read in this manner is compared with personal information that has been pre-registered, to authenticate the individual. A card with a magnetic strip has been used for the ID card storing the personal information. In addition, a so-called IC card having a semi-conductor chip has also been proposed for storing such personal information therein.
In Japanese Unexamined Patent Publication No. 6(1994)-199080, only the face image is trimmed from the image data according to the internal processing that is not described specifically.
In Japanese Unexamined Patent Publication No. 2000-36032, how the face is trimmed is described specifically. However, accuracy of trimming becomes lower if a color of human skin is different among pictured subjects, since the trimming method uses the skin color.
In addition, in the case of photography of a person to obtain an image from which a face image is trimmed, a size and a position of the face included in the image may change according to a distance from a photographing apparatus and a position of the person in an angle of view at the time of photography (hereinafter collectively referred to as the photography position). If the size and the position of the face included in the face image change due to the photography position, trimming cannot be carried out with high accuracy. In this case, the photography position may be determined accurately at the time of photography. However, determining the photography position with high accuracy at each time of photography is extremely troublesome.